1. Field of the Invention
The present invention relates to an ink sheet cartridge and a recording apparatus using said ink sheet cartridge.
2. Related Background Art
Today, along with the progress of information processing systems, various information processing equipments have been developed. Among these equipments, the recording apparatus such as a facsimile terminal equipment or printer has been used extensively not only in offices, but also in homes.
In connection with these facsimile terminal equipments, the so-called thermal recording method is generally used in which the thermosensible sheet coloring with the application of heat is used to facilitate the miniaturization, but recently, the facsimile terminal equipment with the so-called thermal transfer recording method using the ink sheet has been also developed. In the facsimile terminal equipment with the thermal transfer recording method, there are advantages that the plain paper can be used as a recording sheet, and images can be clearly recorded.
And such a facsimile terminal equipment has a structure of opening an upper cover (recording cover) of main body by turning it upward for easy exchange of the ink sheet, in which the upper cover has an ink sheet cassette with the ink sheet contained therein. A driving mechanism for driving a take-up reel shaft within the ink sheet cartridge is mounted on the upper cover, as the cartridge previously described, to simplify the structure. And in view of the weight of the driving mechanism, the take-up reel shaft is located closer to a rotation shaft around which the upper cover is turned than a supply reel shaft.
However, as the ink sheet is very thin, it may easily produce wrinkles. Thus, in order to load the ink sheet into a recording apparatus without producing wrinkles of the ink sheet, a simple method for loading has been proposed in which the ink sheet is contained within an ink sheet cartridge, which is then loaded into the recording apparatus.
However, as a large tension is applied to the take-up reel in winding up the ink sheet, the take-up reel may sometimes be flexed.
For example, in the so-called multi-print method which performs the recording by providing a difference between the conveying speed of recording sheet and that of ink sheet, the rotational force is transmitted to a reel gear integral with the take-up reel, thereby rotating the take-up reel to wind the ink sheet around the reel, whereby the take-up tension is very large.
Furthermore, the ink sheet between a platen roller and the take-up reel shaft may receive the heat from a recording head, as well as losing the ink on an ink layer of a recording portion in the ink sheet. Such ink sheet is likely to produce some wrinkles, so that the take-up reel shaft must be subjected to a large force to wind the ink sheet without wrinkles.
Therefore, there was a problem that if the strength of the take-up reel shaft was weak, the take-up reel shaft might be flexed, causing some irregular conveyances of the ink sheet, and disordering recorded images.
On the other hand, a tension from the ink sheet is also exerted on the side of a supply reel shaft. But as the material for use with such an apparatus has generally a property that when its strength increases, the weight also increases, there was a problem in that a reel shaft having the same strength as the take-up reel shaft is directly used for the supply reel shaft which is located further away from the rotation shaft as compared with the take-up reel shaft.